+ mm-migration-avoid-unneeded-nodemask_t-initialization.patch added to -mm tree

+ mm-migration-avoid-unneeded-nodemask_t-initialization.patch added to -mm tree

[Andrew Morton]

The patch titled
     Subject: mm/migration: avoid unneeded nodemask_t initialization
has been added to the -mm tree.  Its filename is
     mm-migration-avoid-unneeded-nodemask_t-initialization.patch

This patch should soon appear at
    https://ozlabs.org/~akpm/mmots/broken-out/mm-migration-avoid-unneeded-nodemask_t-initialization.patch
and later at
    https://ozlabs.org/~akpm/mmotm/broken-out/mm-migration-avoid-unneeded-nodemask_t-initialization.patch

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------------------------------------------------------
From: Miaohe Lin <linmiaohe@huawei.com>
Subject: mm/migration: avoid unneeded nodemask_t initialization

Avoid unneeded next_pass and this_pass initialization as they're always
set before using to save possible cpu cycles when there are plenty of
nodes in the system.

Link: https://lkml.kernel.org/r/20220318111709.60311-8-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/migrate.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/mm/migrate.c~mm-migration-avoid-unneeded-nodemask_t-initialization
+++ a/mm/migrate.c
@@ -2370,8 +2370,8 @@ out_clear:
  */
 static void __set_migration_target_nodes(void)
 {
-	nodemask_t next_pass	= NODE_MASK_NONE;
-	nodemask_t this_pass	= NODE_MASK_NONE;
+	nodemask_t next_pass;
+	nodemask_t this_pass;
 	nodemask_t used_targets = NODE_MASK_NONE;
 	int node, best_distance;
 
_

Patches currently in -mm which might be from linmiaohe@huawei.com are

mm-shmem-make-shmem_init-return-void.patch
mm-memcg-remove-unneeded-nr_scanned.patch
mm-mremap-use-helper-mlock_future_check.patch
mm-mlock-fix-two-bugs-in-user_shm_lock.patch
mm-compaction-use-helper-isolation_suitable.patch
mm-migration-remove-unneeded-local-variable-mapping_locked.patch
mm-migration-remove-unneeded-out-label.patch
mm-migration-remove-unneeded-local-variable-page_lru.patch
mm-migration-fix-the-confusing-pagetranshuge-check.patch
mm-migration-use-helper-function-vma_lookup-in-add_page_for_migration.patch
mm-migration-use-helper-macro-min-in-do_pages_stat.patch
mm-migration-avoid-unneeded-nodemask_t-initialization.patch
mm-migration-remove-some-duplicated-codes-in-migrate_pages.patch
mm-migration-fix-potential-page-refcounts-leak-in-migrate_pages.patch
mm-migration-fix-potential-invalid-node-access-for-reclaim-based-migration.patch
mm-migration-fix-possible-do_pages_stat_array-racing-with-memory-offline.patch